PRACTICAL PROBLEMS 337 



offspring. On the contrary, owing to the increased elimina- 

 tion of the unfit, slum life strengthens the race. But it 

 strengthens it only against the conditions which surround 

 slum life ; the race is no better in any other respect, in brain 

 and muscle for example. Contrariwise, were slum life 

 abolished, the race would, in time, be weakened in its power 

 of resisting the banished conditions; but the individual 

 would be strengthened in many ways immediately. Since, 

 then, the power to exist in slums would be of no advantage 

 in the absence of slums, it would be an unmixed benefit to 

 abolish these physical and moral plague-spots, provided that 

 were done permanently. Undoubtedly as science progresses 

 and the community, especially the governing class, grows 

 more enlightened, this is what will happen. Already some 

 progress has been made, as is proved by the fall in the death- 

 rate. The problem of physical deterioration in connection 

 with slum life, then, is narrowed to the question of improv- 

 ing the lot of the individual. We need have no fears for the 

 race. 



522. But, though conditions adverse to the individual do 

 not tend to cause racial deterioration, beneficial conditions 

 do. The fall in the death-rate and the prolongation of the 

 average length of life indicate that many individuals are now 

 surviving who would have perished formerly. The improve- 

 ment is manifested in all classes of the community, and is 

 due to the advance made in medical science, both with 

 respect to the treatment of individuals and in the department 

 of Public Health. 



523. The science of Public Health (sanitation, preventive 

 medicine), unless it makes great advances in the future, is 

 able to operate only within narrow limits. As practised at 

 present it exercises supervision over the food, water and 

 housing of the community, and endeavours to abolish or 

 diminish zymotic disease. By improving the water supply 

 it has greatly reduced the prevalence of, and ultimately may 

 quite eliminate, water-borne maladies. By letting air and 

 light into the dwelling-houses and by preventing over- 

 crowding it has lessened earth-borne disease. But in all 

 probability this reduction of mortality torn consumption, 

 though it may continue till slums have quite disappeared, is 

 not permanent. As generations pass, as the numbers of the 

 unfit increase through lessened elimination, as the race 

 regresses, the task of the sanitary reformer will grow in 

 magnitude and complexity. The disease is difficult to detect 

 in its earlier stages, especially in very resistant sufferers, in 



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